In removing certain automotive transmission from the engine for servicing, it is necessary to remove the starter motor (after disconnecting the battery to protect against damage from a short) and the cover plate to gain partial access to the interior of the torque converter bell housing for removal of cap screws. Then the starter motor has to be reinstalled and the battery reconnected. The starter motor is then energized briefly, or "bumped", to rotate the torque converter through a small arc to bring at least one of the cap screws, which connect the torque converter to the drive plate, into somewhat more accessible position for removal. With the starter in position, the mechanic must work around it to remove the screw and it is essential that the torque converter drive plate be carefully positioned to provide access for a tool to remove each cap screw. After the first cap screw is removed, the starter is again energized to rotate the torque converter through another small arc to a position to expose the next cap screw or two, to enable the mechanic to loosen those so exposed. This procedure is repeated until all cap screws have been removed. Moreover, the rotation of the ring gear with the starter motor is very difficult to control, and the starter motor is conditioned for rotation in one direction only. Accordingly the torque converter may inadvertently be allowed to overrun the relatively short arc of movement in which a cap screw is accessible below the engine, in which case the starter motor has to be energized again either to rotate the torque converter through almost a complete revolution for another attempt, or to skip it from the moment and go on to the next boss and cap screw. When all cap screws are finally removed, the mechanic again disconnects the battery before removing the starter motor from the transmission housing, and then removes all other fasteners necessary to remove the transmission-converter from the vehicle.
Thus, it is a tedious, time-consuming process just to remove the cap screws that link the torque converter drive plate to the crank shaft to enable servicing of the torque converter, and the mechanic has to go through the reverse process to replace the cap screws after the torque converter has been serviced. Moreover, a mechanic may prefer to just tighten each of the series of cap screws partially and then return to each in sequence to tighten them completely, one at a time, in order to maintain relative uniformity in load. So, it may take two or more of such incremental full turns of the torque converter for complete replacement and tightening of all cap screws.